Covering device for skylights

ABSTRACT

A covering device for a skylight in a flat roof including a frame mounted in the skylight opening and having horizontally disposed reflector panels that are inclined relative to the roof. The frame is rotatable and can be tilted or the panels can be tilted to follow the relative movement of the sun.

United States Patent 11 1 1111 3,709,583 Pfannkuch et al. 1 1 Jan. 9, 1973 1541 COVERING DEVICE FOR SKYLIGHTS 2,022,144 11/1935 Nicolson ..350/264 x [76] Inventors: Heinrich Pfannkuch, Berrschess f trasse 16; Adolf Saxberger, Nassl- 2'9l8023 121959 1 strasse both of Munich; Fritz ettc er ..350/258X Schnebel, 1 Greimelbers FOREIGN PATENTS OR APPLICATIONS Greimelberg, all of Germany [22] F d Feb 19 1971 115,955 10/1942 Australia "350/264 e 1 [21] APPL 116,853 Primary Examiner-Samuel S. Matthews Assistant Examiner-E. M. Bero 30 F A r P i D Attorney-Milton J. Wayne, Wolfgang G. Fasse and oreign pp lcation nor ty ata Erwin Koppel Feb. 27, 1970 Germany ..P 20 09 372.5

[57] ABSTRACT 5" 350/260 A covering device for a skylight in a flat roof including s a f e ou i t e opening d ha ing [58] Flew of Search 350/258 264 horizontally disposed reflector panels that are inclined References Cited relative to the roof. The frame is rotatable and can be tilted or the panels can be tilted to follow the relative UNITED STATES PATENTS movement of the 2,858,734 11/1958 Boyd ..350/260 13 Claims, 4 Drawing Figures PATENTEDJAN 9 ms 3.709.583

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SHEET 2 OF 2 COVERING DEVICE FOR SKYLIGII'IS The present invention relates to a covering device for skylights, particularly in flat roofs of buildings, having triple reflector panels inclined with respect to the horizontal.

BACKGROUND OF THE INVENTION In flat buildings and in the upper floors of buildings having several floors, skylights in light domes, saddleshaped roofs and lantern roofs, as well as north-light roofs have often been used for illuminating with the daylight. With these skylights the problem that constantly arises is to protect the lighted spaces against undesirable direct sun radiations and the glare and heat caused thereby.

It is for this reason that north-light roofs, for example, have been constructed so that the windows admit only the light from the north. A covering means that is often used consists in lattices, that is, assemblies of panels impervious to light and adjustable in their angular position. But these lattices considerably reduce the entrance of light in the spaces to be protected inasmuch as they shut off not only the portion of light rays to be excluded but also the diffused light portion that in itself is not inconvenient and is desirable for lighting the room.

Further, it has been sought to achieve protection against the sun by means of a partially permeable coating of glazing but this results in a reduced entrance of light and also in an undesirable heating of the glazing by absorption of the heat energy that appears.

All the above mentioned means of protection against undesirable solar radiation have the disadvantage of being associated with a great loss of light that far exceeds the measure that would be required for guarding against direct sunlight, and the entrance of diffused light is also prevented.

It has also been proposed for covering skylights to use clear, transparent covering elements that on the side facing the space to be protected have a reflector structure as known in reflecting elements. But the disadvantage of those covers is that the elements having reflector structure only effectively reflect the radiations that appear directly when these radiations fall in a range of i 22.5" in respect to the line perpendicular to the flat side of the covering element. Thus, the reflection can no longer be effectively obtained when the light source is at an angle larger than 45.

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the problem of protecting to a great extent against direct solar light and heat radiation in skylights, particularly in flat roofs of buildings, and yet admitting as great as possible a portion of diffused sunlight over a broad range of the reflector principle whereby light rays striking the exposed surface at particular angles of incidence are reflected three times within the discrete reflector elements and are subsequently discharged in a direction opposite and parallel to the incoming rays (see R.W. Pohl, Optik und Atomphysik, p. 23, 1958 (Springer Verlag, Berlin, Gottingen, Heidelberg) One embodiment of the invention consists in that the supporting frame is mounted on horizontal rollers and is guided on its outer periphery by perpendicular rollers. The supporting frame can be connected with a driving motor for the rotational movement about the central axis, with the driving motor either synchronized with the movement of the sun, or being designed as a stepping motor that effects a gradual rotative movement.

According to a further embodiment of the invention, the supporting frame is adapted to be tilted on one side against the horizontal position, or the reflector panels in the supporting frame are adjustable in their inclination with respect to the horizontal position.

In a still further embodiment of the covering device according to the present invention, the supporting frame is disposed in a space between a lower glass pane and a dome, or saddle-shaped roof or other similar roof construction of clear, transparent material, it being possible that the space be sealed. The lower glass pane can be constructed with a diffuser.

Another embodiment of the invention consists in that the space between the dome, or saddle-shaped roof or similar roof construction and the lower glass pane is sealed against moisture diffusion.

By means of the covering device for skylights according to the present invention, the reflector panels are synchronized with or gradually adjusted according to the movement of the sun so as to ensure the full effectiveness of the reflector structure at any time of the day.

The light transmittence, despite the effective avoidance from direct light and heat radiation, is about percent higher than in hitherto commercially available clear and transparent materials that are about equivalent in heat protection.

The invention makes it possible to use completely transparent covers instead of the covers made partly impervious to light and heat such as lantern roofs, thus compensating extensively for the loss of direct light radiation for the illumination.

The lighting of the spaces covered with the device according to the invention will therefore always be of a diffuse, glare-free nature with high lighting power.

The invention makes it possible to plan and carry out the arrangement of skylights independently of the geographic location and of particular conditions of the plot of land inasmuch as it is no longer required to align certain parts of the cover, for instance, toward the north side as in the north-light roofs.

An example of the invention is illustrated in the drawings and described in more detail herebelow. In the figures:

FIG. 1 is a diagrammatic side view of a covering device according to the invention, partly in section;

FIG. 2 is a top view of a supporting frame of the covering device with polished reflector panels diagrammatically illustrated; and

FIG. 3 is a sectional view through the supporting frame along line IIIIII in FIG. 2; and

FIG. 4 is a perspective view of a saddle-shaped roof construction with covering devices according to the invention.

In FIG. 1 is diagrammatically illustrated in a side view, a supporting frame 1 having triple reflector panels 2 inclined against the horizontal. The supporting frame 1 is circular and disposed in a corresponding circular skylight 3 of a flat roof 4. The supporting frame is mounted on horizontally disposed rollers 5 and is guided along its periphery by means of perpendicularly disposed rollers 6.

The skylight 3 is sealed at its lower surface with respect to the inner side of the space by a glass pane 7 and is sealed upwardly by a dome 8 of transparent glass. The glass pane 7 serves, together with the dome 8, to keep the reflector panels from becoming dusty. The glass pane 7 can have a slight glaze or can be constructed with a diffuser to render ineffective the spectral decomposition of the light produced by the reflector. The dome 8 must consist of a clear and transparent material to permit the unhindered and directed passage of the light that is then correspondingly reflected by the reflector panels.

By mounting the supporting frame 1 on the horizontal rollers 5 and being guided by the perpendicular rollers 6 so that the supporting frame is rotatable about a central axis perpendicular to the horizontal, it is possible to rotate the supporting frame to follow the azimuth of the sun so as to always align the reflector panels 2 toward the sun.

The reflector panels 2 are disposed in the supporting frame 1 with an inclination to the horizontal line so that their reflecting action is always available from the lowermost to the uppermost position of the sun. The difference of the declination of the sun, as it has already been mentioned, can of course amount to as much as 45, as otherwise the reflector panels are no longer fully effective. But the declination of the sun in the region of the equator to the middle latitude is so high that this angle of 45 is exceeded. Therefore, means have been provided to lift the entire system on one side and thus adapt it to the position of the sun at the moment when the limit of effectiveness of the reflector panels rigidly disposed in the supporting frame is exceeded. In FIG. 1 the position of the supporting frame 1 that is lifted or tilted on one side with respect to the horizontal position is indicated by dotted lines.

Another possibility of adapting the reflector panels to the position of the sun when the declination is too high is to make the panels individually movable about their longitudinal axis and adjust them accordingly to the position of the sun so that the sun rays strike every time within the range of 22.5 at both sides of the line perpendicular to the flat side of the panels.

In FIG. 2 is shown a top view of the supporting frame with the reflector panels according to the invention. The upper edge 9 of the supporting frame 1 is designed, at least on part of the periphery, as a toothed rim in which a pinion 10 is engaged. The pinion 10 is driven by a driving motor 11. This driving motor can work so as to move the supporting frame 1 with the reflector panels synchronized with the movement of the sun, or

it can be constructed as a stepping motor that gradually moves the supporting frame so as always to ensure an angle of incidence of the sunlight of at most i- 22.5 in respect to the line perpendicular to the surface of the reflector panels.

In FIG. 3 is shown a section through the supporting frame along line III-III in FIG. 2. The arrangement of the reflector panels inclined against the horizontal can be clearly seen here.

FIG. 4 shows a saddle-shaped roof construction 12 on a flat roof 4 diagrammatically represented in perspective. In the rectangular aperture 13 in the flat roof is disposed a shutter 14 having light openings 3 to each receive the supporting frome l with reflector panels 2 according to the invention.

The space between the dome 8 or saddle-shaped roof construction 12 and the lower glass pane 7 can be sealed against moisture diffusion so that a double glazing of the dome or of the roof construction can be avoided.

A modification of the rotating or tilting movement of the supporting frame lies in initially disposing the supporting frame in a plane inclined against the horizontal line as shown, for instance, by the dotted position of the supporting frame in FIG. 1. Under certain circumstances, the tilting capacity of the frame in operation can be eliminated when the rotating movement of the frame takes place about a central axis perpendicular to its plane of the frame with the central axis being inclined with respect to the roof position.

What we claim is:

1. A covering device for a skylight for use on sub-.

stantially horizontal roofs of buildings, comprising a supporting frame mounted in the skylight, said frame having an upper surface disposed in a plane and a central axis of rotation perpendicular to the plane of said upper surface of the supporting frame; a plurality of individual, planar triple reflector panels parallely mounted in said frame, said panels being inclined with respect to the plane of the upper surface of the supporting frame; and means for rotating said frame about its said axis to follow the azimuth of the sun thereby confining the angle of incidence of the direct rays of the sunlight to within an approximate angle of i 22.5 with respect to a line perpendicular to the said planar reflector panels.

2. A covering device according to claim 1 inwhich the supporting frame for the triple reflector panels is circular.

3. A covering device according to claim 1 in which the supporting frame is mounted on horizontal rollers and guided on its external periphery by perpendicular rollers.

4. A covering device according toclaim l in which the supporting frame is connected with a driving motor for the rotational movement about the central axis.

5. A covering device according to claim 4 in which the driving motor is a stepping motor.

6. A covering device according to claim 1 in which the supporting frame is disposed in a space between a lower glass pane and a dome made of transparent material.

7. A covering device according to claim 1 in which the supporting frame is disposed in a space between a lower glass pane and a saddle-shaped roof construction made of transparent material.

fusion.

12. A covering device according to claim 1, wherein said central axis is disposed so as to be inclined with respect to the substantially horizontal position of the roof.

13. A covering device according to claim 1, wherein said supporting frame is disposed in said skylight in such a way as to be tiltably adjustable with respect to the substantially horizontal position of the roof. 

1. A covering device for a skylight for use on substantially horizontal roofs of buildings, comprising a supporting frame mounted in the skylight, said frame having an upper surface disposed in a plane and a central axis of rotation perpendicular to the plane of said upper surface of the supporting frame; a plurality of individual, planar triple reflector panels parallely mounted in said frame, said panels being inclined with respect to the plane of the upper surface of the supporting frame; and means for rotating said frame about its said axis to follow the azimuth of the sun thereby confining the angle of incidence of the direct rays of the sunlight to within an approximate angle of + OR 22.5* with respect to a line perpendicular to the said planar reflector panels.
 2. A covering device according to claim 1 in which the supporting frame for the triple reflector panels is circular.
 3. A covering device according to claim 1 in which the supporting frame is mounted on horizontal rollers and guided on its external periphery by perpendicular rollers.
 4. A covering device according to claim 1 in which the supporting frame is connected with a driving motor for the rotational movement about the central axis.
 5. A covering device according to claim 4 in which the driving motor is a stepping motor.
 6. A covering device according to claim 1 in which the supporting frame is disposed in a space between a lower glass pane and a dome made of transparent material.
 7. A covering device according to claim 1 in which the supporting frame is disposed in a space between a lower glass pane and a saddle-shaped roof construction made of transparent material.
 8. A covering device according to claim 6, in which the lower glass pane is constructed with a diffuser.
 9. A covering device according to claim 7 in which the lower glass pane is constructed with a diffuser.
 10. A covering device according to claim 6 in which the space between the dome and the lower glass pane is sealed against moisture diffusion.
 11. A covering device according to claim 7 in which the space between the saddle-shaped roof construction and the lower glass pane is sealed against moisture diffusion.
 12. A covering device according to claim 1, wherein said central axis is disposed so as to be inclined with respect to the substantially horizontal position of the roof.
 13. A covering device according to claim 1, wherein said supporting frame is disposed in said skylight in such a way as to be tiltably adjustable with respect to the substantially horizontal position of the roof. 